title: The effect of metabolic risk factors on the natural course of gastro-oesophageal reflux disease.
abstract: OBJECTIVE
  The effect of metabolic risk factors on the natural course of gastro-oesophageal reflux disease (GORD), which remains elusive, was quantified.
  
  
  METHODS
  The population included 3669 subjects undergoing repeated upper endoscopy. Data were analysed using a three-state Markov model to estimate transition rates (according to the Los Angeles classification) regarding the natural course of the disease. Individual risk score together with the kinetic curve was derived by identifying significant factors responsible for the net force between progression and regression.
  
  
  RESULTS
  During three consecutive study periods, 12.2, 14.9 and 17.9% of subjects, respectively, progressed from non-erosive to erosive disease, whereas 42.5, 37.3 and 34.6%, respectively, regressed to the non-erosive stage. The annual transition rate from non-erosive to class A-B disease was 0.151 per person year (95% CI 0.136 to 0.165) and from class A-B to C-D was 0.079 per person year (95% CI 0.063 to 0.094). The regression rate from class A-B to non-erosive disease was 0.481 per person year (95% CI 0.425 to 0.536). Class C-D, however, appeared to be an absorbing state when not properly treated. Being male (relative risk (RR) 4.31; 95% CI 3.22 to 5.75), smoking (RR 1.20; 95% CI 1.03 to 1.39) or having metabolic syndrome (RR 1.75; 95% CI 1.29 to 2.38) independently increased the likelihood of progressing from a non-erosive to an erosive stage of disease and/or lowered the likelihood of disease regression. The short-term use of acid suppressants (RR 0.54; 95% CI 0.39 to 0.75) raised the likelihood of regression from erosive to non-erosive disease.
  
  
  CONCLUSIONS
  Intraoesophageal damage is a dynamic and migratory process in which the metabolic syndrome is associated with accelerated progression to or attenuated regression from erosive states. These findings have important implications for the design of effective prevention and screening strategies.
authors.affiliation: Division of Biostatistics, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Y-C
authors.initials: YC
authors.lastname: Lee
authors.forename: A M-F
authors.initials: AM
authors.lastname: Yen
authors.forename: J J
authors.initials: JJ
authors.lastname: Tai
authors.forename: S-H
authors.initials: SH
authors.lastname: Chang
authors.forename: J-T
authors.initials: JT
authors.lastname: Lin
authors.forename: H-M
authors.initials: HM
authors.lastname: Chiu
authors.forename: H-P
authors.initials: HP
authors.lastname: Wang
authors.forename: M-S
authors.initials: MS
authors.lastname: Wu
authors.forename: T H-H
authors.initials: TH
authors.lastname: Chen
mesh_terms: D000368:Aged; D000428:Alcohol Drinking / Q000009:adverse effects; D016009:Chi-Square Distribution; D018450:Disease Progression; D004947:Esophagus / Q000378:metabolism / Q000473:pathology; D005260:Female; D005764:Gastroesophageal Reflux / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D008297:Male; D008390:Markov Chains; D024821:Metabolic Syndrome / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D008954:Models, Biological; D009765:Obesity / Q000378:metabolism / Q000473:pathology; D011446:Prospective Studies; D012306:Risk; D012307:Risk Factors; D012737:Sex Factors; D012907:Smoking / Q000009:adverse effects; D013997:Time Factors